Healthcare Data GlossaryPayer
Medicare: Definition and Healthcare Context
Full name: Federal Medicare Health Insurance Program
Medicare is the federal health insurance program administered by CMS for people age 65 or older, certain younger individuals with disabilities, and people with End-Stage Renal Disease. Established by Title XVIII of the Social Security Act in 1965, Medicare covers inpatient hospital care (Part A), outpatient and physician services (Part B), prescription drugs (Part D), and managed care alternatives (Part C / Medicare Advantage). In 2024, Medicare covered approximately 67 million beneficiaries.
Last updated: 2026-05-31Reviewed by: Dr. Jennifer Montecillo, MD — Gullas College of Medicine, 2019. Non-practicing medical reviewer.
How it’s used
- CMS PECOS Medicare Provider Enrollment: PECOS tracks Medicare enrollment status for all providers who bill the program.
- CMS QPP MIPS: MIPS applies to clinicians billing Medicare fee-for-service above specified volume thresholds.
- Healthcare Cost Report Information System (HCRIS): hospitals and other facilities submit annual Medicare cost reports that feed the public HCRIS database.
- CMS Care Compare: most Care Compare quality metrics are derived from Medicare claims data and Medicare-certified facility surveys.
Frequently asked questions
- Who is eligible for Medicare?
- Medicare covers people age 65 or older, younger individuals with certain disabilities, and people with End-Stage Renal Disease (ESRD) regardless of age.
- What are the parts of Medicare?
- Medicare Part A covers inpatient hospital care; Part B covers outpatient and physician services; Part C (Medicare Advantage) is a managed care alternative; Part D covers prescription drugs.
- How many people are covered by Medicare?
- As of 2024, approximately 67 million people are enrolled in Medicare.